Push button switch



Jan. 12, 1960 A. F. RAAB 2,921,170

PUSH BUTTON SWITCH Filed July 31, 195"! N VEN TOR fl/voms w E A 445 EM 6. 015m United States Patent Ofiice Patented Jan. 12, 1369 PUSH BUTTON SWITCH Andrew F. Raab, Chicago, Ill., assignor to Carter Parts Company, Chicago, Ill., a corporation of Illinois Application July 31, 1957, Serial No. 675,490 8 Claims. (Cl. 200-159) The present invention relates to a push button switch for making and breaking an electric circuit.

It is an object of the present invention to provide an improved switch of this character which is constructed and arranged to assure clean contacts by virtue of the self-wiping action of the contacting elements.

It is another object of the present invention to provide an improved switch which is characterized by the simplicity of the components and the case with which they can be assembled so as to provide a low cost device of uniform, high quality construction.

It is another object of the present invention to provide an improved switch of the foregoing character, wherein the components can be assembled and retained in their assembled positions merely by clamping together a portion of the switch housing, thereby requiring minimum labor and machinery cost in assembling the switch.

It is still another object to provide an improved electric contactor made from a single thin sheet of resilient conductive material which has helical contacting portions which are self-wiping when pressed against spaced electrical contacts by virtue of the limited rotational movement that occurs when the helical portions are collapsed.

Other objects of this invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

In the drawings:

Figure l is a section taken through the longitudinal axis of one embodiment of the present invention;

Figure 2 is an end elevation as seen from the left of Figure 1;

Figure 3 is a section taken on the line 3-3 of Figure 1; and

Figure 4 is an end elevation as seen from the right of Figure 1.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

Referring now to the drawings, a more detailed description of the invention will be given. The push button switch has a one-piece cylindrical housing 12 which may be made in any suitable manner, such, for example, as by die casting. The housing 12 is hollow and has open ends. The one end portion 14 has a larger diameter than the small end portion 16. The latter has a threaded outer surface 18 by which the switch 10 can be screwed into an instrument panel, or the like.

The large and small portions 14 and 16 join at the internal shoulder 20 which faces the large open end.

A plunger 22, which may be formed from any suitable platsic dielectric material, extends through the hollow housing 12 and has a push button end portion 24 for pressing the plunger 22 inward when it is desired to close a circuit through the switch 10. The plunger 22 has an enlarged intermediate portion 26 which seats on the shoulder 20 and prevents the plunger 22 from sliding out the small end of the housing 12. The plunger 22 also has a portion 28 of reduced diameter extending through the opening of the large end of hous-' ing 12.

The large open end of housing 12 is closed by a dielectric terminal board 30 which has two spaced terminals 32 and 34 mounted therein, such terminals extending through board 30 into housing 12 to form two spaced contacts, only one of which is shown in Figure l at 36. The dielectric terminal board also has an aperture 38 therein through which the plunger end 28 projects.

A one-piece electric contactor 40 is carried by the plunger 22 for spanning the two spaced contacts on the ends of terminals 32 and 34. The contactor 40 is made from any conductive resilient sheet metal which can be stamped into the shape shown in Figures l and 3.

Referring to these figures, it can be seen that the contactor 40 has an annular shape so that it fits over the end portion 28 of plunger 22. The contactor has two arcuate portions 42 and 44 which are pressed out of the plane of the contactor so as to be segments of helices. By virtue of this construction, the plunger 22 can be moved further into the housing 12, carrying the contactor 40 with it, and when the arcuate portions engage, respectively, the contacts on the ends of terminals 32 and 34, the portions will be pressed back into the plane of the contactor 40 causing limited rotational movement of such portions about the axis of plunger 22. This will have the eifect of wiping clean the contacting electrical elements. Thus, a good electrical connection will always be assured between the terminals 32 and 34 via the contactor 40.

The contactor 40 and plunger 22 will be urged away from the contacts on terminals32 and 34 by the action of the coil spring 46. The latter is held in compression between the dielectric terminal board 30 and the contactor 40 so that it tends to push the plunger 22 against the shoulder 20 of housing 12.

In order to prevent relative rotation between the contactor 40, plunger 22 and housing 12, the enlarged portion 26 of plunger 22 has a pair of diametrically opposed axial slots 46 and 48. The slot 48 is adapted to receive the radially inwardly projecting rib 50 in the wall of housing 12.. The other slot 46 is adapted to receive the tongue 52 which is deflected out of the plane of contactor 40. By virtue of this construction and arrangement the plunger 22 and its contactor 40 can move axially within housing 12 and the arcuate portions 42 and 44 will remain in proper alignment with the contacts on ends of terminals 32 and 34, thereby assuring proper wiping action between these parts.

In assemblying the components of the switch 10, it is only necessary to hold the housing 12 in an upright position, with the enlarged end uppermost. The plunger 22 can then be inserted in the position shown with slot 48 fitting over the rib 50. The annular contactor 40 can then be put in place with its tongue 52 in slot 46. Coil spring 46 will then be dropped over the end of plunger 22 after which the terminal board 30 with its terminals in place will be dropped over the end of plunger 22 against the shoulder 54 in housing 12. The outer end 56 of the housing 12 can then be crimped or pressed over so as to clamp the terminal board in a fixed position.

The switch 10 is then ready to be installed for use by screwing the threaded portion 18 into an instrument panel, or the like. closed merely by pressing button 24 which: results in contactor 40 spanning the contacts within the housing closing a circuit therethrough. The circuit is opened upon release of button 24 by the action ofspring 46.

Having thus described my invention, I claim:

1. An electric switch comprising a one piece housing open at opposite ends, a plunger mounted in said housing for reciprocal movement and having one end extending out of one of the open ends of said housing, a terminal board closing the other open end of said housing, a pair of spaced terminals mounted on said board and extending through the latter into said housing to provide therein a pair of spaced contacts, said plunger having a onepiece contactor mounted thereon for spanning the pair of spaced contacts when the plunger is pressed further into said housing, said one piece contactor being formed from resilient electrical-conductive material with the contacting portions thereof being generally helical-shaped segments extending toward said spaced contacts so that when said contacting portions are pressed against said spaced contacts limited rotational movement of said contacting po'rtions will occur wiping the contacts and said contacting portions clean, and a spring operatively mounted in said housing for urging said plunger away from said contacts.

2. An electric switch comprising a hollow housing open at opposite ends, the opening at one end being smaller than the opening at the other end so that a shoulder is formed in the housing facing said other end, a plunger extending through the opening of said one end into said housing and having an enlarged portion for seating on said shoulder, a dielectric terminal board mounted over the opening at said other end, a pair of spaced terminals extending through said board into said housing to provide therein a pair of spaced contacts, a one-piece contacto'r seated on the enlarged portion of said plunger for spanning the pair of spaced contacts when the plunger is moved from its seat further into said housing, said one piece contactor being fo'rmed from resilient electricalconductive material with the contacting portions thereof being generally helical-shaped segments extending toward said spaced contacts so that when said contacting portions are pressed against said spaced contacts limited rotational movement of said contacting portions will occur wiping the contacts and said contacting portions clean,

and a spring positioned between said terminal board and said one-piece contactor for urging the latter into its seated position on the plunger and for urging said onepiece contactor and said plunger away from said spaced contacts and toward said shoulder.

3. An electric switch comprising a hollow housing open at opposite ends, the opening at one end being smaller than the opening at the other end so that a sho'ul der is formed in the housing facing said other end, a plunger extending through the opening of said one end into said housing and having an enlarged portion seated on said shoulder and a portion of reduced diameter extending into the opening of said other end, a dielectric terminal board mounted over the opening at said other end and having an aperture therein fitting over the reduced end portion of said plunger to provide a guide for movement of said plunger, a pair of spaced terminals mounted on said board extending through the latter into said housing to provide therein a pair of spaced contacts, an annular one-piece contacto'r carried on the enlarged portion of said plunger for spanning the pair of spaced contacts when the plunger is moved from its seat further into said housing, said one piece contactor being formed from resilient electrical-conductive material with the contacting portions thereof being generally helical-shaped segments extending toward said spaced contacts so that when As explained above, the switch is said contacting portions are pressed against said-spaced contacts limited rotational movement of said contacting portions will occur wiping the contacts and said contacting po'rtions clean, and a coil spring fitted over the reduced end portion of the plunger with its opposite ends in engagement with said terminal board and said contactor for urging the latter away from said contacts.

4. An electric switch comprising a hollow housing open at opposite ends, the opening at one being smaller than the opening at the other end so that a shoulder is formed in the housing facing said other end, a plunger extending through the opening of said one end into said housing and having an enlarged portion seated on said shoulder and a portion of reduced diameter extending into the opening of said other end, a dielectric terminal board mounted over the Opening at said other end and having an aperture therein fitting over the reduced end portion of said plunger, a pair of spaced terminals extending through the latter into said housing to provide therein a pair of spaced contacts, an annular one-piece contactor carried on said portion of reduced diameter and seated on the enlarged portion of said plunger for spaning the pair of spaced contacts when the plunger is moved from its seat on said shoulder further into said housing, said contactor having two helix-shaped portions projecting from its periphery toward said contacts for engagement therewith when said plunger is pushed from said shoulder, and a coil spring fitted over the reduced end portion of the plunger with its opposite ends in engagement with said terminal board and said contacto'r for urging the latter away from said contacts.

5. An electric switch comprising a hollow housing open at opposite ends, the opening at one end being smaller than the opening at the other end so that a shoulder is formed in the ho'using facing said other end, a plunger extending through the opening of said one end into said housing and having an enlarged portion seated on said shoulder and a portion of reduced diameter extending into the opening of said other end, a dielectric terminal bo'ard mounted over the opening at said other end and having an aperture therein fitting over the reduced end portion of said plunger, a pair of spaced terminals extending through the latter into said housing to provide therein a pair of spaced contacts, an annular onepiece contactor carried on said portion of reduced diameter and seated on the enlarged portion of said plunger for spanning the pair of spaced contacts when the plunger is moved from its seat on said shoulder further into said housing, said contactor having two helix-shaped portions projecting from its periphery toward said contacts for engagement therewith when said plunger is pushed from said shoulder, and a coil spring fitted over the reduced end portion of the plunger with its opposite ends in engagement with said terminal board and said contactor for urging the latter away from said contacts, said plunger and housing having cooperating means to prevent relative rotation therebetween.

6. An electric switch comprising a hollow housing open at opposite ends, the opening at one end being smaller than the opening at the other end so that a shoulder is formed in the housing facing said other end, a plunger extending through the opening of said one end into said housing and having an enlarged portion seated on said shoulder and having a portion of reduced diameter extending into the opening of said other end, a dielectric terminal board mounted over the opening at said other end and having an aperture therein fitting over the reduced end portion of said plunger, a pair of spaced terminals extending through the latter into said housing to provide therein a pair of spaced contacts, an annular one-piece contacto'r carried on the portion of reduced diameter of said plunger for spanning the pair of spaced contacts when the plunger is moved from its seat on said shoulder further into said housing, said contactor having two helix-shaped portions projecting from its periphery toward said contacts for engagement therewith when said plunger is pushed from said shoulder, and a coil spring fitted over the reduced end portion of the plu'nger with its opposite ends in engagement with said terminal board and said contactor for urging the latter against said enlarged portion of the plunger and away from said contacts, said plunger, contactor and housing having cooperating means to prevent relative rotation therebetween.

7. An electric switch comprising a hollow one-piece body open at opposite ends, said body having two aligned cylindrical portions of difierent diameters, the portion of smaller diameter having a threaded outer surface, the interior of said housing having a shoulder at the juncture of said portions facing the larger open end, a plunger extending through said housing and having an enlarged portion intermediate its ends seated on said shoulder, a dielectric terminal board mounted over the larger open end and having an aperture therein fitting over the end portio'n of said plunger to act as a guide therefor, a pair of spaced terminals extending from said terminal board into said housing to provide therein a pair of spaced contacts, an annular one-piece contactor carried on the enlarged portion of said plunger for spanning the pair of spaced contacts when the plunger is moved from its seat on said shoulder, said contactor having two helix-shaped portions projecting toward said contacts for engagement therewith when the plunger is pushed from its seat, said plunger, contactor and housing having cooperating means to prevent relative rotation therebetween, and a spring operatively mounted in said housing for urging said plunger and its associated contactor away from said contacts and for cooperating in retaining said contacto'r in its operative position on said enlarged portion.

8. An electric switch comprising a hollow one-piece body open at opposite ends, said body having two aligned cylindrical portions of different diameters, the'portion of smaller diameter having a threaded outer surface, the interior of said housing having a shoulder at the juncture of said portions facing the larger open end, a plunger extending through said housing and having an enlarged portion intermediate its ends seated on said shoulder, a dielectric terminal board mounted over the larger open end and having an aperture therein fitting over the end portion of said plunger for guiding axial movement of the later, a pair of spaced terminals extending from the terminal board into said housing to provide therein a pair of spaced contacts, an annular onepiece contactor fitting over one end carried on the enlarged port-ion of said plunger for spanning the pair of spaced contacts when the plunger is moved from its seat on said shoulder, said contactor having two inclined arcuate portions projecting toward said contacts for engagement therewith when the plunger is pushed from its seat, said plunger, contactor and housing having cooperating means to prevent relative rotation therebetween, said cooperating means including axial slots in the enlarged portion of said plunger, an axially extending rib on the inner wall of said housing which fits into one of said slots and a tongue extending from said contactor into another of said slots, and a spring operatively mounted in said housing for urging said plunger and its associated contactor away from said contacts.

References Cited in the file of this patent UNITED STATES PATENTS 

